The Panthers will face California Baptist University at 6 p.m. on Wednesday.
Alexis Johnson scored a game-high 22 points and grabbed 11 rebounds. Lady Walker scored 17 and pulled down 10 rebounds. Ashley Smith added 14 points, Rachael Pecota chipped in 10 and Rejoice Spivey dished out 10 assists to lead Union (27-4).
Britteny Tatum scored 18 and Alexis Carter scored 17 to go with 10 rebounds for Columbus State (30-2), who had their 22-game win streak snapped.
Johnson and Kishona Sutton came up big late for the Panthers, who trailed the Cougars 63-57 entering the fourth quarter.
Johnson’s basket with 1:43 remaining gave the Panthers a 74-73 lead. Johnson then hit a free throw with less than a minute left to make it 75-73.
Virginia Union’s defense held and Kishona Sutton made two free throws with 20.1 seconds remaining for a 77-73 lead. Johnson added another free throw with three seconds left to make it 78-73.
The Panthers outscored the Cougars 21-10 in the fourth quarter.
The Union women are looking for their second national championship in school history after winning the 1983 national title.